Comparison of wild accessions of g. barbadense l. from Peru and Brazil via microsatellite markers

Abstract

Peru and Brazil are recognized as primary and secondary centers of G. barbadense L., which is a species that stands out for producing long cotton fiber. However, since its introduction in Brazil, G. barbadense L. populations have reduced its occurrence and genetic variability. Thus, the objective of this study was to compare the diversity level among wild accessions of G. barbadense L. from Peru and Brazil, for conservation and management of its genetic resource. Fifteen accessions from Peru, 13 from Brazil, and the cultivar Pima S7 were analyzed using 29 microsatellite markers. Genetic diversity in the 29 accessions was analyzed using descriptive statistics and methods based on distance index (UPGMA, 3D projection, and principal coordinate analysis), as well as ancestry model (Structure 2.3.4). Based on these analyses, it is verified that there is similar variability level between the Brazilian and the Peruvian accessions. At least 5 Brazilian accessions come from gene pools different from those of the rest of the Brazilian accessions. Peru's accessions originate from six different gene pools. Nine out of 29 accessions present genetic admixture of at least three different gene pools. Variability of Peruvian and Brazilian accessions may prove to be crucial for cotton crop worldwide.